A spot in the next round is at stake on Tuesday, when Emma Navarro goes up against Jessica Pegula in the US Open quarterfinal. Jessica Pegula has won 3 in a row and 8 of the last 10 overall. Emma Navarro is rolling — 3 straight wins, 6 of 10 in recent play.

There's a wide gap in our ratings on hard, and our number follows from it. Navarro needs several things to break right at once; the percentages say they usually don't.